Thread protector



Patented June 19, 1945 THREAD PROTECTOR Ernest W. Krause, Wheeling, W. Va., assignor to Krause Stamping & Manufacturing'Company, Wheeling, W. Va., a corporation of West Virginia Application November 22, 1943, Serial No. 511,309

' (c1. 1ss 9s 1 Claim. This invention relates to thread protectors for protecting screw threads from damage during the time the threaded element, such as pipe, is being transported, handled or stored. Not only does the invention afford protection to the threads from injury by chance violent contact with another object likely to harm the threads, but it serves as well toexclude dirt, sand, and other similar foreign substances and thus eliminate chance injury to the threads from. this cause. g

In describing the invention in detail, reference is herein made to the accompanying drawing,

in -which Figure 1 is a vertical sectional view of the invention applied to the external threads of an end of a pipe;

Figure 2 is an enlarged fragmentary vertical sectional view of the protector designed for application to an externally threaded object;

Figure 3 is a sectional view taken on line 33 of Fig. l with the pipe removed; and

Figure 4 is a vertical sectional view of a modifled form of the invention showing one of its applications for internal threads.

Referring to Fig. 1 of said drawing, the reference numeral l designates a section 'ofone end ofa pipe, both ends of which are provided with external screw threads.

The reference numeral 2 in said drawing designates a sheet metal shell of a gauge appropriately heavy for the purpose for which the shell is designed, the shell being of slightly larger diameter than the pipe I.

Provided-interiorly of the shell 2 isa bushinglike insert or liner 3, said liner preferably having a length materially less than the exterior shell 2 and being fabricated from sheet metal of substantially lighter gauge than said shell.

The liner3 may be immovably fixed within the shell by any of a number of available means common in the art. In the drawing, it is shown as being maintained rigidly in position by a plurality of registering nodule-like studs l formed simultaneously in the shell and liner by suitable rolls applied to the assembled parts.

This means of permanently attaching the two j piecesis for purpose of illustration only since other and equally satisfactory means are now well known and common in the art.

The liner 3 has formed in its side wall, as, for instance, by means of rolling, a, set of threads 5. As shown in the drawing, the threads are formed in that portion of the liner adjacent its outer end and do not extend throughoutthe entire length of the liner. Moreover, it may here be pointed out that the threads 5 are rolled into the comparatively light gauge sheet metal wall of the liner 3 sotha't they will accommodate themselves to substantially any size or type of external screw thread borne by the end of the pipe I. In other words, the gauge of sheet metal from which the liner is formed is suificiently light and flexible that it, together with its rolled threads, will become adapted to and mesh with substantially any size or type of screw thread borne by a, .pipe of a size for which the protector is designed. Thus, the lighter gauge liner affords means of attachment of the protector to the pipe substantially preventing chance displacement while the heavier smooth wall of the shell 2 servesas a shield to absorb damaging shocks to prevent injury to the threads therefrom.

Theouter ends of the shell 2 and liner 3 are turned inward, as shown at 6, to form a flange or seat which forms a stop as well as a seal to prevent access of objectionable foreign substances.

Figure 4 depicts a typical protector for internally threaded elements, as, for example, the end of an oil well sucker rod 1. As illustrated. the device comprises a sheet metal shell having a male member 8 adapted to be received within the tapped bore 9 of the end of the sucker rod. The shell is provided at its outer end with an outwardly and downwardly turned flange 9' adapted to embrace the end of the sucker rod.

' The inner portion of the male portion 8 is encased within a sheet metal cap l0. Said cap is fabricated from sheet metal of a gauge lighter the side walls of the cap and shell are spaced away from each other to provide a slight intervening space. Said cap may be fixedto the shell by crimping, as shown at l2, but any other appropriate means of attachment may be employed. 'A series of threads I3 is rolled in the cap Ill to become engaged with the internal screw threads of the bore 9. Arectangularlyshaped slot I4 is provided in the inner end of the shell toaccommodate an appropriate tool for attaching and detaching the protector. The lighter gauge cap l0 with its versatile threads affords means of attachment of the protector to the threaded element while the heavier smooth wall of the shell serves as a shield to absorb chance damaging shocks likely to injure the delicate screw threads of the bore 9. Moreover, as will be noted from an examination of' associated with said shell, said element having,

a continuous rolled thread for connection to pipe threads of varying pitch, and means for rigidly connecting the shell and element in telescoping relation to each other.

ERNEST w. KRAUSE. 

